Analysis of selected metallic impurities in soft drinks marketed in Lagos, Nigeria

Abstract

Twenty brands of soft drinks commonly consumed in Lagos, Nigeria were analyzed for lead, cadmium, nickel, silver, chromium and zinc using standard biochemical procedures. The aim was to determine whether the concentrations of toxic metals in commonly consumed soft drinks are below or above the upper limit for each of the metals as set by World Health Organization (WHO). Results showed that cadmium was present in four of the samples at a concentration ranging from 0.023 to 0.158 mg/L, lead was present in three of the samples at a concentration ranging from 0.5045 to 3.0275 mg/L, nickel was present in six of the samples at a concentration ranging from 0.016 to 0.063 mg/L while silver was absent in all of the samples. Some of the samples analyzed can be said to be safe for human consumption because the values of the metals were below the allowable limits as set by WHO while others could not be said to be safe as the levels of metals were above the allowable limits set by WHO. Therefore, it is suggested that health authorities and soft drink producing companies should pay more attention to the sources of these metals in soft drinks.

Key words: Soft drinks, toxic metals, maximum contaminant level, atomic absorption spectrophotometry.